docs: def _addItemMultiPart(self,
                            itemParameters,
                            filePath):
          """
          The secret sauce behind the addByPart workflow
          Inputs:
             itemParatmers - ItemParamter class
             filePath - full disk path location.
          Output:
             UserItem class
          """
          url = self._location + "/addItem"
          params = {
              "f": "json",
              'multipart' : 'true',
              "filename"	: os.path.basename(filePath)
          }
          res = self._post(url=url,
                           param_dict=params,
                           securityHandler=self._securityHandler)
          if 'id' in res:
              itemID = res['id']
              iUrl = "%s/items/%s" % (self.location, itemID)
              ui = UserItem(url=iUrl,
                            securityHandler=self._securityHandler,
                            proxy_url=self._proxy_url,
                            proxy_port=self._proxy_port)
              res = ui.addByPart(filePath=filePath)
              res = ui.commit(wait=True)
              up = ItemParameter()
              up.title = itemParameters.title
              up.tags = itemParameters.tags
              up.filename = os.path.basename(filePath)
              up.type = itemParameters.type
              ui.updateItem(itemParameters=up)
  
              update_url = ui.root.replace('/rest/', '/') + "/update"
  
              data = {'title': itemParameters.title,
                     'tags': itemParameters.tags,
                     'filename': os.path.basename(filePath),
                     'type': itemParameters.type,
                     'f': 'json'}
              for k,v in itemParameters.value.items():
                  if k not in data.keys():
                      if isinstance(v, bool):
                          data[k] = json.dumps(v)
                      else:
                          data[k] = v
              res = self._post(url=update_url,
                               param_dict=data,
                              securityHandler=self._securityHandler)
              ui.refresh()
              return ui
          return None